1. Field of the Invention
The present invention relates to a mobile communications terminal, a service area calculation apparatus which calculates a service area of a mobile communications network, and a method of calculating the service area.
2. Description of the Related Art
As wireless LANs (local area network) have recently become common, various providers provide mobile communications services in various spots.
Such mobile communications services generally use a wireless communication method. Therefore, if a user makes a contract with service providers, he/she can be provided with various services anytime and anywhere with one mobile communications terminal.
However, service areas of the mobile communications services mentioned above are discretely formed. It is thus difficult for the user to know where the service areas are located.
In addition, in a method disclosed in the patent document (Jpn. Pat. Appln. KOKAI Publication No. 2002-223218), an address (MAC address) unique to a wireless terminal, positional information thereof and a communication quality concerned with the position are stored so as to form a plane view that tells whether or not the communication quality is good in a plane where the wireless terminal can be disposed.
Under the circumstances described above, it is desired that the various service areas should be generally grasp.
In the Patent document described above, it is found out whether or not the communication quality is good in a plane where the wireless terminal can be located, for example, based on a communication state in the wireless terminal. It can not be applied to grasp of the respective service areas that belong to a plurality of mobile communications networks.
In other words, the Patent document described above, does not allow the service area of the mobile communications network to be grasp by a third party except for its operator. Therefore, it is difficult to grasp conditions of a plurality of service areas formed by various operators at their discretion.